Stemless prosthesis anchor component

ABSTRACT

A shoulder assembly is provided which includes a base member including a collar; a helical structure extending from the collar in a distal direction; and a first pathway projecting distally of the collar and through the helical structure adjacent to an inner periphery thereof, the first pathway being generally transverse to the helical structure and extending in a space between successive portions of the helical structure; and a locking device comprising a proximal support and a first arm projecting distally of the proximal support, the first arm configured to be disposed in the first pathway projecting distally of the collar when the proximal support is disposed adjacent to the collar; where the first arm is disposed through bone in the space between successive portions of the helical structure when the shoulder assembly is implanted.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 17/407,250, filed on Aug. 20, 2021, which is a divisionalapplication of U.S. patent application Ser. No. 16/320,860, filed Jan.25, 2019, now U.S. Pat. No. 11,129,724, issued on Sep. 28, 2021, whichis a § 371 application of PCT International Application No.PCT/US2017/038843, filed on Jun. 22, 2017, which claims priority to U.S.Provisional application No. 62/368,036, filed on Jul. 28, 2016, thecontents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to a stemless prosthesis anchor componentof a joint prosthesis.

Description of the Related Art

Skeletal joints have a variety of configurations providing for a widerange of smooth movement of two or more bones relative to each other.For example, in a shoulder joint, the head of the humerus interacts withthe glenoid cavity of the scapula in a manner similar to a “ball andsocket” joint. Over time, it may become necessary to replace a joint,such as the shoulder joint, with a prosthetic joint. The prostheticjoint can include components mounted to one, two or more than two bonesat the joint. For example, the prosthetic joint can include a humeralcomponent, a glenoid component or both a humeral and a glenoidcomponent.

Conventional humeral components include a humeral head jointed to astem. The stem is configured to be inserted into a medullary canal ofthe humerus. In certain cases, insertion of the stem disadvantageouslyrequires bone to be removed to fit the stem to the medullary canal dueto patient-to-patient anatomical variation. Another disadvantage of thisapproach is that integration of the stem into the bone through a naturalprocess of bone ingrowth can make it difficult to remove the humeralcomponent if it becomes necessary to replace the humeral component withanother device.

A stemless humeral component may be used to address some of thedisadvantages of conventional humeral components. Stemless humeralcomponents can decrease the amount of bone loss in preparing the humerusto receive the component and decrease the complexity of the jointreplacement procedure.

Stemless humeral component designs can be more challenging to secure tothe humerus. Conventional stemless designs rely on bone ingrowth forstrength. While such designs perform well over time, there is a risk inthe early days and weeks after surgery where such ingrowth has not yetoccurred that the stemless humeral component will be dislodged from thehumerus. Dislodgement may also occur due to backing out after beinginserted, excessive wear, forces applied thereto during a revisionsurgery or other high load conditions.

SUMMARY OF THE INVENTION

Accordingly, there is a need for additional stemless components orprostheses designed to preserve bone in initial implantation whileenhancing initial pull-out and back-out resistance. Preferably enhancedinitial dislodgement resistance will also provide excellent long termfixation.

In one embodiment, a shoulder assembly is provided that includes a basemember and a locking device. The base member includes a collar, ahelical structure, and a first pathway projecting distally of thecollar. The helical structure extends from the collar in a distaldirection. The first pathway projects distally of the collar and throughthe helical structure. The first pathway is disposed adjacent to aninner periphery of the helical structure. The first pathway is generallytransverse to the helical structure and extending in a space betweensuccessive portions of the helical structure. The locking device has aproximal support and a first arm that projects distally of the proximalsupport. The first arm is configured to be disposed in the first pathwaythat projects distally of the collar when the proximal support isdisposed adjacent to the collar. The first arm is disposed through bonein the space between successive portions of the helical structure whenthe shoulder assembly is implanted.

In some embodiments, a kit can be provided that includes a shoulderassembly as described above, an anatomic articular component, and areverse articular component. The anatomic articular component ismateable with the shoulder assembly. The anatomic articular componenthas a convex articular surface adapted to articulate with a concavesurface of or on a scapula of a patient. The reverse articular componentis mateable with the shoulder assembly. The reverse articular componentcomprises a concave articular surface adapted to articulate with aconvex surface on a scapula of a patient. The reverse articularcomponent can include a separate tray component for mating an articularsurface to the base member.

In another embodiment, a prosthesis assembly is provided that includes abase member that has a helical structure and a first pathway. The basemember has a first end and a second end. The helical structure extendsbetween the first end and the second end. The first end comprises adistal or medial end in some applications. The second end comprises aproximal end or a lateral end in some applications. The first pathway isaccessible from the second end and is directed toward the first endthrough the helical structure. The first pathway is located inward of anouter periphery of the helical structure, e.g., adjacent to an innerperiphery of the helical structure. The first pathway is generallytransverse to the helical structure. The first pathway extends in aspace between successive portions of the helical structure. Theprosthesis assembly includes a locking device that has a support memberand a first arm that projects away from the support member. The firstarm is configured to be disposed in the first pathway when the supportmember is disposed adjacent to the second end of the base member. Thefirst arm is disposed through bone in the space between successiveportions of the helical structure when the prosthesis assembly isimplanted.

The prosthesis assembly discussed above can be mated with a proximalhumerus. The prosthesis assembly discussed above can be mated with otheranatomy as well, such as a glenoid of a scapula. The prosthesis assemblydiscussed above can be mated with a bone adjacent to an elbow joint,such as a distal humerus or a proximal radius. The prosthesis assemblydiscussed above can be mated with a bone adjacent to a wrist joint, suchas a distal radius. The prosthesis assembly discussed above can be matedwith a bone adjacent to the hip, such as a proximal femur. Theprosthesis assembly discussed above can be mated with a bone adjacent toa knee joint, such as a distal femur or a proximal tibia. The prosthesisassembly discussed above can be mated with a bone adjacent to an anklejoint, such as a distal tibia or a proximal talus

In another embodiment, a method of implanting a prosthesis is provided.The method includes advancing by rotation a base member into a boneadjacent to a joint. The bone can include an epiphysis of a humerus of apatient. The bone can include a glenoid of a scapula of a patient. Thebone can include a distal portion of a humerus adjacent to an elbowjoint. The bone can include a proximal portion of a radius adjacent toan elbow joint. The bone can include a distal portion of a radiusadjacent to a wrist joint. The bone can include a proximal portion of afemur adjacent to a hip joint. The bone can include a distal portion ofa femur adjacent to a knee joint. The bone can include a proximalportion of a tibia adjacent to a knee joint. The bone can include adistal portion of a tibia adjacent to an ankle joint. The bone caninclude a proximal portion of a talus adjacent to an ankle joint. Thebase member comprising a helical structure configured to engagecancellous bone of the epiphysis or other portion of any of the bonesset forth above. A locking device is advanced by linear translation intothe base member. The locking device has at least one arm adapted to spana gap between adjacent portions of the helical structure. The lockingdevice contacts the cancellous bone in the gap.

In another embodiment, a glenoid assembly is provided. The glenoidassembly includes a base member and a plate member. The base member hasa medial end and a lateral end. The base member has a helical structurethat extends between the medial end and the lateral end and a firstpathway. The first pathway is accessible from the lateral end and isdirected toward the medial end. The first pathway can extend through thehelical structure and can be located inward of an outer periphery of thehelical structure, e.g., adjacent to an inner periphery of the helicalstructure. The first pathway can be generally transverse to the helicalstructure and can extend in a space between successive portions of thehelical structure. The plate member has a flange and a first arm thatprojects away from the flange. The first arm is configured to bedisposed in the first pathway when the plate member is disposed adjacentto the lateral end of the base member. The first arm is disposed throughbone in the space between successive portions of the helical structurewhen the prosthesis assembly is implanted.

Any feature, structure, or step disclosed herein can be replaced with orcombined with any other feature, structure, or step disclosed herein, oromitted. Further, for purposes of summarizing the disclosure, certainaspects, advantages, and features of the inventions have been describedherein. It is to be understood that not necessarily any or all suchadvantages are achieved in accordance with any particular embodiment ofthe inventions disclosed herein. No aspects of this disclosure areessential or indispensable.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages are described belowwith reference to the drawings, which are intended to illustrate but notto limit the inventions. In the drawings, like reference charactersdenote corresponding features consistently throughout similarembodiments. The following is a brief description of each of thedrawings.

FIG. 1 is a perspective view of one embodiment of a stemless shoulderassembly shown mounted in a humerus, and further illustrating a kitincluding anatomic and reverse shoulder articular components;

FIG. 2 is an exploded view of the stemless shoulder assembly shown inFIG. 1 ;

FIG. 3A is a side view of the base member of FIG. 2 ;

FIG. 3B is a top view of the base member of FIG. 2 ;

FIG. 3C is a cross-sectional view of the base member of FIG. 2 taken atsection plane 3C-3C;

FIG. 3D is a cross-sectional view of the base member of FIG. 2 taken atsection plane 3D-3D;

FIG. 4 is a side view of one embodiment of a locking component, which isa component configured to control, e.g., reduce or eliminate and/orcontrol rotation of a base member or of a helical structure of aprosthesis assembly;

FIG. 5 is a top, proximal side, or medial side view of the lockingcomponent of the FIG. 4 ;

FIG. 6A is a detail view of one embodiment of an engagement feature thatcauses the locking component of FIG. 4 and the base member of FIGS. 3Aand 3B to be engaged;

FIG. 6B is a detail view of another embodiment of an engagement featurethat causes the locking component and the base member to be engaged at alocation within the helical structure;

FIG. 7 is a cross-sectional view of the stemless shoulder assembly ofFIG. 2 with the assembly disposed in the humeral head;

FIGS. 8-16 illustrate various methods for implanting a prosthesisassembly of FIGS. 1-7 into a portion of a bone;

FIG. 17 is a side view of the stemless shoulder assembly of FIG. 2coupled with an anatomic articular component of the kit illustrated inFIG. 1 ;

FIG. 18A is a side view of the stemless shoulder assembly of FIG. 2coupled with a reverse articular component of the kit illustrated inFIG. 1 ;

FIG. 18B shows a reverse shoulder prosthesis including a reversearticular component coupled with the humerus and a convex glenoidcomponent, sometimes referred to as a glenoid sphere, coupled with thescapula;

FIG. 19 is a schematic side view of a glenoid of a scapula of a shoulderof a patient with a reverse shoulder prosthesis assembly disposedtherein;

FIG. 20 is a cross-sectional view of the reverse shoulder prosthesisassembly shown in FIG. 19 taken at section plane 20-20;

FIG. 21 is an exploded perspective view of the reverse shoulderprosthesis assembly illustrated in FIG. 20 showing features of thearticular surface of a glenoid sphere;

FIG. 22 is an exploded view of the reverse shoulder prosthesis assemblyillustrated in FIG. 20 showing features of a bone engaging side of aplate member;

FIG. 23 is a cross-sectional view of the reverse shoulder prosthesisassembly of FIG. 20 taken at section plane 23-23 shown in FIG. 22 ;

FIG. 23A shows aspects of a base member of the shoulder assembly of FIG.19 ;

FIG. 24 is a schematic side view of a proximal femur having a prosthesisassembly similar to that of FIGS. 1-7 disposed therein in connectionwith a hip joint procedure;

FIG. 25 is a schematic side view of a distal portion of a long bone ofan arm, e.g., of the humerus or radius, having a prosthesis assemblysimilar to that of FIGS. 1-7 disposed therein in connection with anelbow or wrist joint procedure;

FIG. 26 is a schematic side view of a knee joint showing a prosthesisassembly similar to that of FIGS. 1-7 disposed in the distal femur andin the proximal tibia thereof;

FIG. 27 is a schematic side view of an ankle joint showing a prosthesisassembly similar to that of FIGS. 1-7 disposed in the distal tibia andin the proximal talus thereof; and

FIG. 28 shows comparative tip out performance of an embodiment asdisclosed herein compared to a conventional stemless implant.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While the present description sets forth specific details of variousembodiments, it will be appreciated that the description is illustrativeonly and should not be construed in any way as limiting. Furthermore,various applications of such embodiments and modifications thereto,which may occur to those who are skilled in the art, are alsoencompassed by the general concepts described herein. Each and everyfeature described herein, and each and every combination of two or moreof such features, is included within the scope of the present inventionprovided that the features included in such a combination are notmutually inconsistent.

FIG. 1 shows a kit 80 that includes a shoulder assembly 100. The kit 80can include one or both of an anatomic articular component 84 and areverse articular component 88. The anatomic articular component 84 cancomprise a one-piece structure including a convex articular surface 90disposed on a proximal or lateral side and a tapered projection 92disposed on a distal side thereof. The reverse articular component 88can comprise a two-piece structure including a tray 94 and an insert 96.In other embodiments, the articular component 88 has a one-piececonfiguration. In other embodiments, the articular component 88 has amonolithic configuration. Monolithic embodiments can comprise a onematerial configuration. Monolithic embodiments can comprise two or morematerial. The insert 96 can mate with the tray 94 in any suitablemanner, such as by interference fit or snap fit. The tray 94 can includea tapered projection 98. FIG. 18B shows that the kit 80 also can includea glenoid sphere 99 and corresponding components for anchoring theglenoid sphere in a glenoid. The insert 96 is shown in just oneembodiment in which the tray is angled, such that a plane intersectingthe medial side of the insert 96 is at an angle to the side that facesthe shoulder assembly 100 providing a thicker superior portion. In otherembodiments the insert 96 is angled, such that a plane intersecting themedial side of the insert 96 is at an angle to the side that faces theshoulder assembly 100 providing a thicker inferior portion. In otherembodiments the insert 96 is not angled, such that the planeintersecting the medial side of the insert 96 is substantially parallelto the side that faces the shoulder assembly 100.

FIG. 1 shows the shoulder assembly 100, as further described below inconnection with FIGS. 2-7 , implanted in an exposed face F of a humerusH. The assembly 100 has a recess 102 in which further components of aprosthetic shoulder joint can be secured. The assembly 100 and therecess 102 enable the humerus H to be fitted with either an anatomicalshoulder by receiving the anatomic articular component 84, moreparticularly, the projection 92 or a reverse shoulder component 88 byreceiving the projection 98 either initially or as part of a revisionprocedure. Methods of using the kit 80 to implant the shoulder assembly100 as part of a shoulder prosthesis are discussed below in connectionwith FIGS. 8-16 . FIGS. 19-26 show that further embodiments can be usedbeyond humeral application and beyond shoulder joint procedures. FIG. 27illustrates the performance of certain embodiments compared to a priorart design. While incremental differences in these embodiments andmethods are discussed below, it is to be understood that features ofeach embodiment can be combined with features of the other embodiments,as appropriate.

I. Humeral Shoulder Assemblies Having Rotation Control Locking Devices

FIGS. 1 and 7 show the shoulder assembly 100 applied to a shoulderjoint. The assembly 100 can provide secure stemless connection to thehumerus H. The shoulder assembly 100 provides for simple implantationbecause a base member thereof can be directly threaded into cancellousbone without being mated to another pre-placed base member. The shoulderassembly 100 can be fully retained within a head h of the humerus H.FIG. 7 shows that the distal-most portion of the assembly 100 preferablycan be disposed in the humeral head h. The assembly 100 does not have astem or other member that protrudes beyond the head h into a medullarycanal of the humerus. This approach is less invasive and simpler thanprocedures involving placement of a stem in a medullary canal. In otherembodiments illustrated in part in FIG. 10 by the creation of a recessedsurface s having a depth accommodating a thickness of a proximal portionof the assembly 100, the assembly 100 may be recessed within the humeralhead of the humerus H such that a proximal face 105 the assembly 100 isflush with respect to a cut surface of the bone.

FIG. 2 shows that the assembly 100 includes a base member 104 and alocking device 108. The base member 104 is advanced into a bonystructure such as cancellous bone in use. As discussed further below abone surface may be exposed by resection or reaming, followed bythreading of the base member 104 into a newly exposed bone surface. Theassembly 100 also includes the locking device 108. The locking device108 includes a plurality of arms 110. In particular, the arms 110 extendoutward or distal from proximal support 132. The arms 110 can include afirst arm, a second arm, and a third arm. The arms 110 can becircumferentially spaced equal distances from each other, e.g., about120 degrees apart in one embodiment. In another variation, the arms 110include three arms, with two of the three arms spaced 90 degrees fromeach other and a third arm spaced 135 degrees from one of the other twoarms. The locking device 108 may include four or more arms 110. If thearms 110 include four arms, the arms can be circumferentially spaced 90degrees apart. If the arms 110 include two arms, the arms can becircumferentially spaced 180 degrees apart. The arms 110 are advancedthrough apertures 124 in the base member 104. In one embodiment, itshould be noted that the number of arms 110 corresponds to an equalnumber of apertures 124. When so advanced, the arms 110 are disposedwithin the base member 104 in a manner that the arms 110 cross a spacebetween portions, e.g., successive portions, of the base member 100.When so positioned, the arms 110 are also disposed within bone. Thus,two zones of the arms 110 can cross successive or adjacent portions ofthe base 104 and an intervening portion of the arms 110 can cross bonein a space between the successive or adjacent portion of the base. Inthis position, the arms 110 control, e.g., resist, rotation of the basemember 104 relative to the bone such that the shoulder assembly 100 issecured against backing out of the bone upon implantation.

FIG. 2 also shows that the locking device 108 also includes a proximalsupport 132. The proximal support 132 is coupled with the arms 110 in amanner discussed further below. The proximal support 132 has a centralaperture 136 disposed within an inner periphery thereof and extendsoutward from the central aperture 136 to an outer periphery 135. Theinner and outer periphery of the proximal support 132 are received in arecess 140 formed in the base member 104. In one configuration therecess 140 and the proximal support 132 are configured such that a flushconnection is provided between the proximal support 132 and the proximalface of the base member 104. The proximal support 132 can be connectedto the base member 104 in an at least partially recessed position in theproximal face of the base member as discussed further below inconnection with FIG. 6A.

FIGS. 2 and 3B show that the proximal face of the base member 104 caninclude a raised inner portion 148 and a raised outer portion 152. Theouter raised portion 152 extends around an outer periphery 154 of thebase member 104. The raised portion 148, 152 are proximally orientedprojections relative to a recessed surface 156. The recessed surface 156can be disposed distally of one or both of the inner portion 148 and theouter portion 152. The raised inner portion 148 can define an aperturefor access into the recess 102, which is configured for mating witharticular components as discussed below. Each of the raised innerportion and the raised outer portion 148, 152 can comprises annularstructures. The recessed surface 156 can comprise an annular portion.The apertures 124 can be formed in the recessed surface 156. In oneembodiment the apertures 124 extend radially between the inner raisedportion 148 and the outer raised portion 152. The apertures 124 canextend from the inner raised portion 148 to the outer raised portion152.

The proximal face of the base member 104 also can include a toolinterface 158 that enables the base member to be advanced by an inserterinto bone, as discussed below in FIG. 14 . The tool interface 158includes three notches in an inward side of the outer raised portion152. In other embodiments, the tool interface 158 can include aperturesin the recessed surface 156, notches in the inner raised portion 148,projections from any surface of the proximal face of the base member 104or any combination of these features. Also, the tool interface 158 canprovide access for a removal tool to engage the locking device 108. Asdiscussed below, the locking device 108 includes a spring arm 168 and aremoval tool can be applied at the tool interface 158 to compress thearm 168 to disengage the locking device from the base member 104. Insome cases, an inserter tool can engage one or more apertures 124 in thebase member 104 upon insertion.

One or more structures for securing the locking device 108 to the basemember 104 can be provided as discussed further below. For example thelocking device can have an engagement feature 164 disposed on theproximal support 132 that is adapted to engage a corresponding featureon the proximal face of the base member 104. The engagement feature 164can include an actuatable member that can move into a secure positionrelative to the recess 140 of the base member 104. As discussed below inconnection with FIGS. 5 and 6A, the engagement features 164 can includea spring arm 168 to engage an overhang of the recess 140. As shown inFIG. 2 , one embodiment comprises a plurality of actuatable members,e.g., a plurality of spring arms 168. The spring arms 168 can be spacedapart, e.g., providing equal angle separation between adjacent springarms 168. In one embodiment, the number of spring arms 168 matches thenumber of arms 110. Each spring arm 168 can be spaced apart from eacharm 110 as discussed further below.

In another embodiment, a serration 172 is provided between the arms 110of the locking device 108 and the base member 104 as discussed ingreater detail below in connection with FIG. 6B. The serration 172 is anexample of a one-way connection that can be provided between the arms110 and the base member 104. Other one-way connections can be providedin addition or in place of the serration 172, such as a ratchet, a barb,or one or more spring arms.

FIGS. 2-3B show further details of embodiments of the base member 104.In some embodiments, the base member 104 can include various featuresdescribed in PCT publication WO2016/094739, the entirety of which ishereby incorporated by reference herein. The base member 104 has a firstend 204, a second end 208 and a body 212 that extends between the firstend 204 and the second end 208. The base member 104 can comprise alength L between the first end 204 and the second end 208 that is lessthan a dimension of an articular surface of typical epiphysis to amedullary canal of a typical humerus. As such, the first end 204 can bedisposed within the epiphysis when the second end 208 is at a surface ofthe bone, as shown in FIG. 7 . The second end 208 can be disposed at oron a superior medial resection plane of a humerus while the first end204 is well within the epiphysis. This enables the first end 204 to stopshort of a medullary canal of the humerus when the base 104 is fullyimplanted, which allows the bone between the first end 204 and themedullary canal to remain unaltered and also simplifies the procedure tothe extent that any normal access to and preparation of the medullarycanal is not needed. In various embodiments, the length L can be betweenabout 15 mm and about 30 mm, between about 18 mm and about 25 mm,between about 18 mm and about 24 mm, between about 21 mm and about 27mm, between about 24 mm and about 29 mm. The length L can be about 18mm, about 21 mm about 23 mm, about 24, mm about 26 mm and about 29 mm.In one approach, at least a portion of the assembly 100 is patientspecific. For example, the length L can be defined for a specificpatient based on pre-operative planning, such as using two dimensionalor three dimensional imaging. The base member 104 can thereafter bemanufactured for that patient based on the determined dimension L.

The base member 104 can include a collar 220 and a helical structure224. The helical structure 224 is disposed about a cylindrical portion260 of the body 212 of the base member 104. In some embodiments, thehelical structure 224 extends directly from the body 212 and may beconsidered threads of the body 212. The helical structure 224 caninclude one or a plurality of threads, e.g., two, three, four, or morethreads, disposed between the first end 204 and the second end 208. Thethreads can start adjacent to the first end 204 and extend toward, e.g.,entirely to the second end 208. FIG. 3A shows that the threads or otherhelical structure 224 can end at or adjacent to the collar 220. Thethreads or other helical structure 224 can have inner portions 240disposed at or on the body 212 about the recess 102 and outer portions244 disposed along the periphery of the base 104. FIG. 3A shows that thehelical structure 224 has a width defined as the distance between theinner and outer portions 240, 244 that is large, e.g., comprising morethan one-quarter of, e.g., about one-third of, the width of the base 104at a given location. These large threads or other helical structure 224ensure large purchase in the bone. Large purchase provides strongresistance to pullout even prior to any bone ingrowth into the surfacesof the shoulder assembly 100. Generally one or more surfaces of theshoulder assembly 100 that are in direct contact with bone may betextured e.g., coated or layered with a porous material in order toaccelerate tissue ingrowth such as bony ingrowth Therefor good initialresistance to pull-out is advantageous for the patient. At least oneturn of a thread or other helical structure 224 completely surrounds therecess 102, e.g., by completely surrounding the body 212, in someembodiments.

The body 212 surrounds the recess 102, which is configured to mate withan articular component, such as humeral head or a glenoid sphere. In oneembodiment, the body 212 includes a cylindrical portion 260 within whichthe recess 102 is disposed. The cylindrical portion 260 can have anysuitable outside configuration, such as including a textured surfacethat is well suited to encourage bony ingrowth. The cylindrical portion260 can include a generally tapered profile in which a portion at oradjacent to the first end 204 of the base member 100 has a first widthand a portion at or adjacent to the second end 208 of the base member100 can have a second width, the second width being greater than thefirst width. In some embodiments, the cylindrical portion 260 isgenerally rounded and formed a blunt but tapered profile. Thecylindrical portion 260 can have a flat distal surface in someembodiments.

FIG. 7 shows that the cylindrical portion 260 can include a plurality oflayers. For example, an inner layer 264 can be disposed adjacent to therecess 102. The inner layer 264 can include the surface surrounding therecess 102 and can extend away from that surface toward an outer surfaceof the cylindrical portion 260. In one embodiment an outer layer 268 canbe disposed adjacent to the outer surface of cylindrical portion 260.The outer layer 268 can extend from the external surface of thecylindrical portion 260 toward the recess 102. In one embodiment, theouter layer 268 is formed directly on the inner layer 264 although otherarrangements are possible as well. The outer layer 268 can be a porousstructure that is suitable for bony ingrowth.

FIG. 7 also shows that a tool interface 272 can be disposed at oradjacent to the first end 204 of the base member 104. The tool interface272 can include a threaded portion that can mate with a delivery tool,as discussed further below. A lumen 276 can be provided at the first end204 such that access can be provided from the first end 204 through thewall of the cylindrical portion 212 into the recess 102. The lumen 276and recess 102 together provide access for a K-wire or other guidingdevice such that implanting the base member 104 can be controlled in anappropriate manner.

The collar 220 can be disposed at or can comprise the second end 208 ofthe base member 104. The collar 220 can have a transverse width, e.g., adiameter that is suitable for a given condition. For example, thediameter of the collar 220 can be selected such that the entire outerperiphery of the base 104 is within the bone exposed by resection and/orrecessed into such an exposed bone portion, e.g., as illustrated inFIGS. 8-12 . In some embodiments the collar 220 has a diameter of morethan about 25 mm and less than about 60 mm. The collar 220 can have adiameter of between about 30 mm and about 45 mm. The collar 220 can havea diameter of about 33 mm in one embodiment. The collar 220 can have adiameter of about 42 mm in one embodiment. Making the collar 220 aslarge as possible within such bounds provides for better load transferbetween the collar 220 and the humerus H. In one approach, the diameterof the collar 220 can be defined for a specific patient based onpre-operative planning, such as using two dimensional or threedimensional imaging. The base member 104 can thereafter be manufacturedfor that patient based on the determined diameter of the collar. Forexample, the diameter of the collar 220 can be selected such that thecollar covers the cortical rim exposed by resection. The collar 220 canattach to or can be integrally formed with the cylindrical portion 260of the body 212. In one embodiment the collar 220 comprises a transverseflange 290 that extends outward of the recess 102 that is also disposedat the second end 208. An inner portion of the flange 290 can bedisposed adjacent to the recess 102 and can include the inner raisedportion 148. An outer portion of the flange 290 can be disposed outwardof the inner portion. The flange 290 can define the proximal face of thebase member 104. The flange 290 can accommodate the proximal support 132of the locking device 108. FIG. 6A shows that in some embodiments, theflange 290 can at least partially surround a space 294 disposed thereinto receive a portion of the locking device 108. The space 294 can be anannular recess located proximal of the recessed surface 156 and betweenthe inner portion 148 and the outer portion. The space 294 can bebounded by an inner edge of the outer portion 152 and an outer edge ofthe inner portion 148. The flange 290 can engage the spring arm 168 ofthe locking device 108 in the space 294 such that the locking device 108will not be inadvertently disengaged from the base 104 and protrude fromor be removed from the space 294.

FIGS. 2 and 7 show that in some embodiment, the shoulder assembly 100includes a pathway 300 that projects distally of the collar 220. Thepathway 300 can comprise a first pathway. The shoulder assembly 100 caninclude a plurality of pathways, 300 with each pathway corresponding toan arm 110 of the locking device 108. FIG. 3B shows that the base 104can define a plurality of such pathways, e.g., two or three pathwaysconfigured to receive corresponding arms 110. There can be four or morethan four pathways 300. The pathway 300 can have a first end located atthe opening or apertures 124 in the collar 220. The pathway 300 cancontinue down through the base member 104. FIG. 3C shows that thepathway 300 can have one or more segments disposed through the helicalstructure 224. A first segment 300A of the pathway 300 extends from theaperture 124 to a first portion, e.g., a proximal-most turn or portionof the helical structure 224 immediately distal of the collar 220, e.g.,immediately distal of one of the apertures 124. A second segment 300B ofthe pathway 300 extends from the first segment 300A to a second turn orportion of helical structure 224 immediately distal of the first portionof the helical structure. A third segment 300C of the pathway 300 canextend from the second segment to a third turn or portion of helicalstructure 224 immediately distal of the second portion of the helicalstructure 224.

FIGS. 3A and 3D illustrate that at specific locations along the lengthof the base 104 from the first end 204 to the second end 208, thepathway 300 can have a first boundary 304 corresponding to an outersurface or layer of the cylindrical portion 260, for examplecorresponding to a surface of the outer layer 268. The pathway 300 canhave a second boundary 308 at a same location along the length of thebase 104 from the first end 204 to the second end 208 formed by anadjacent portion of helical structure 224. The second boundary 308 caninclude a U-shaped opening in the inner portion 240 of the helicalstructure 224. The U-shaped opening in the inner portion 240 can extendacross the width of the helical structure toward the outer portion 244of the helical structure 224. The U-shaped opening can extend 25%, 35%,45%, 50%, 60%, 70%, 75% or up to 90% of the distance across the width ofthe helical structure 224 from the inner portion 240 toward the outerportion 244. In one embodiment, the helical structure 224 has a taperedconfiguration in which transverse distance between opposite sides of thehelical structure 224 is decreased in the direction of the first end 204compared to the same dimension toward the second end 208. The length ofthe U-shaped opening in successive portions of the helical structure 224in the direction toward the first end 204 is progressively less in someembodiments. As a result the width bounded by a turn of the helicalstructure 224 and the cylindrical portion 260 in the first segment 300Aof the pathway 300 can be greater than the width bounded by a turn ofthe helical structure 224 and the cylindrical portion 260 in the secondsegment 300B. The width in the second segment 300B can be greater thanthe width in the third segment 300C bounded by a turn of the helicalstructure 224 and the cylindrical portion 260. This configuration isadvantageous in accommodating embodiments of the locking device 108having arms 110 that are tapered as discussed further below.

The pathway 300 can extend through one or more spaces between adjacentthreads of the helical structure 224. The pathway 300 can comprise twoor more segments surrounded by portions of the base member 104 and atleast one exposed segment ES. The exposed segments comprise portions ofthe first and second segments 300A, 300B and between the second andthird segments 300B, 300C in some embodiment. The exposed segments ESare exposed in that, unlike the segments 300A, 300B, 300C, the exposedsegments of the pathway 300 are not enclosed circumferentially and thusbone disposed within the helical portion 224 can directly contact thearms 110 in the exposed segment. As such the pathway 300 is bounded bybone matter in the exposed segments.

FIGS. 2, 4 and 5 show the locking device 108 in detail. As discussedabove, the locking device 108 has a proximal support 132 and a first arm110 that projects distally of the proximal support 132. The proximalsupport 132 includes an inner periphery 358, an outer periphery 362 andan annular member 366 disposed therebetween. The inner periphery 358surrounds the central opening 136, which is sized to receive the innerraised portion 148 of the base member 104 if present. The annular member366 is configured to be received in the recess 140, as discussed above.

The first arm 110 is configured to be disposed in the first pathway 300.The pathway 300 projects distally of the collar 220. The first arm 110is disposed distal of the collar 220 when the proximal support 132 isdisposed adjacent to a proximal side of the collar 220 and the first arm110 is in the first pathway 300.

The first arm 110 includes an outer edge 370, an inner edge 374 and aspan 378 disposed therebetween. The first arm 110 includes a first end382 disposed away from the support 132 and a second end 386 disposedadjacent to and in some cases directly coupled to the support 132. Thefirst arm 110 can be tapered, for example with the outer edge 370approaching the inner edge 374 in the direction toward the first end 382and/or with the outer edge 370 diverging away from the inner edge 374 inthe direction toward the second end 386. In one embodiment, oppositefaces 390 of the span 378 are also tapered with at least one of, e.g.,both of, the opposite faces 390 approaching a longitudinal mid-plane Mof an arm 110. The tapering of the arms between the edges 370, 374facilitates providing a tapered profile in the base member 104. Thetapering of the arms between the edges 370, 374, sometimes referred toherein as a radial taper, facilitates insertion of the first end 382into the aperture 124 because the first end 382 is much narrower in thedimension between the edges 370, 374 than the aperture 124 is in theradial direction. The tapering of the arms 110 between the faces 390,sometimes referred to herein as a circumferential taper, facilitatesinsertion of the first end 382 into the aperture 124 because the firstend 382 is much narrower in the dimension between the faces 390 than theaperture 124 is in the circumferential direction.

At least one of the circumferential and radial tapers of the arms 110enables the locking device 108 to easily be advanced through bone matterthat is disposed along the pathway 300.

As discussed above, the first arm 110 is disposed through bone in thespace between successive portions of the helical structure 224, e.g., inthe first segment of the path 300 and in the second segment of the path300, when the humeral shoulder assembly is implanted. The span 378and/or other parts of the arms 110 can be porous to enhance bony ingrownwhen the assembly 100 is implanted. The porous properties can beprovided by a porous metal surface or structure or by other porouslayers disposed on an underlying layer of metal or another material. Atleast the widening of the arms 110 toward the second end 386 increasesthe purchase of bone in the widened area, e.g., in the first segment ofthe path 300 and also in the second segment of the path 300 compared toan arm that is not tapered.

In some embodiments, the arms 110 are not tapered in the radialdirection. For example the arms 110 can have a constant radial dimensionbetween the edges 370 and 374 at a length between, e.g., along theentire length between, the first end 382 and the second end 386. In someembodiments, the arms 110 are not tapered in the circumferentialdirection. For example the arms 110 can have a constant circumferentialdimension between the first end 382 and the second end 386.

As discussed above, the locking device 108 facilitates retaining thebase member 104 in the bone at least by opposing, and in some casescompletely preventing, rotation of the base member that would cause thebase member to back out of the bone into which it has been advanced.Additionally, in some embodiments, it is beneficial to oppose, and insome cases completely prevent, axial movement of the locking device 108away from the base member 104. At the extreme, such movement couldresult in the arms 110 of the locking device 108 completely coming outof the pathways 300 and, indeed, out of the base member 104 completely.It also may be desirable to prevent even lesser movements of the lockingdevice 108 relative to the base member 104. As shown in FIG. 6A, adistal face 402 of the annular member 366 may be positioned in directcontact with a proximal face 404 of the transverse flange 290. Suchcontact can correspond to a proximal face 406 of the annular member 366being distal of a proximal face 408 of the raised outer portion 152. Byrecessing the annular member 366, the interaction of the assembly 100with the articular member of the kit 80 of FIG. 1 is controlled. Forexample, the annular member 366 will not impede advancement of thearticular members into secure engagement with the recess 102.

FIGS. 5 and 6A illustrate various embodiments of axial lockingconfiguration that can be provided in the shoulder assembly 100. Anaxial locking configuration can include the engagement feature 164disposed on the proximal support 132. The spring arm 168 of theengagement feature can include a first end 420 disposed away from theannular member 366 and a second end 424 coupled with the annular member366. The spring arm 168 also has an elongate portion 428 that extendsbetween the first end 420 and the second end 424. The elongate portion428 preferably has an arcuate form and can, in some embodiments, havethe same curvature as a portion of the annular member 366 adjacent tothe second end 424. The elongate portion 428 can be separated from theannular member 366 along a radially inner edge 432 of the elongateportion 428 by a gap G. The gap G and the length of the elongate portion428 can be such that the first end 420 can be moved sufficiently toallow for a snap-fit connection as discussed further below. In oneembodiment, the first end 420 of the spring arm 168 has a deflector 436that facilitates movement of the elongate portion 428 and specificallymovement of the first end 420. FIG. 6A shows that the deflector 436 caninclude an angled surface 460 that initially engages a correspondingangled surface 464 on the base member 104, e.g., on the raised outerportion 152 at the proximal face of the base member. As the arms 110 ofthe locking device 108 are advanced into the paths 300, the annularmember 366 eventually is received in the space 294. At that time, theangled surfaces 460, 464 engage each other, which engagement causes thedeflection of the first end 420 of the spring arm 168. The first end 420is deflected radially inwardly such that the gap G is reduced at leastat the first end 420. This allows a proximal facing surface 472 to moveto a position distal of a distal facing surface 476. After the proximalfacing surface 472 is at a position distal of the distal facing surface476, the spring arm 168 resiliently moves the deflector 436 back to theconfiguration shown in FIG. 5 . At this point, the proximal facingsurface 472 is distal of and aligned with, e.g., positioned under, thedistal facing surface 476, as shown in FIG. 6A. In this configuration,the proximal facing surface 472 blocks the distal facing surface 476from moving proximally. Thus the surfaces 472, 476 prevent the lockingdevice 108 from disengaging from the base member 104.

Another advantageous aspect of the assembly 100 is that the lockingdevice 108 can be quickly and easily disengaged from the base 104. Thetooling interface 158 allows an extraction tool to be disposed betweenthe raised outer portion 152 and the spring arm 168. The extraction toolcan apply a radially inward force on an outer periphery of the elongateportion 428 of the spring arm 168. Compression of the spring arm 168decreases the gap G as the proximal facing surface 472 is moved radiallyinward of the distal facing surface 476. Once the first end 420 isentirely radially inward of the distal facing surface 476, theengagement feature 164 is disengaged from the base 104. If more than onespring arm 168 is provided some or all of the spring arms can becompressed to allow the locking device 108 to be withdrawn from the base104.

FIG. 6B shows additional axial locking configurations that can beprovided in the shoulder assembly 100. In these embodiments, axiallocking can occur at an interface 490 between one or more of the arms110 and one or more of the pathways 300. For example, the serrations 172discussed above can be provided at the interface. In one variation,serrations 172 are disposed along the pathway, e.g., on a surface of thecylindrical member 212 and/or on a surface of the helical structure 224.The serrations 172 can be placed at both the surface of the cylindricalmember 212 and at the helical structure 224. In another embodiment, theserrations 172 could be provided on a surface of the arm 110, e.g., onone of the outer edge 370, the inner edge 374, and/or on one of thefaces 390. The serrations 172 allow for relatively easy insertion of thearms 110 but bite into and oppose withdrawal of the locking device 108to oppose axial disengagement of the locking device 108 from the basemember 104.

The serrations 172 can be disposed along the entire length of theinterface between the arms 110 and the base member 104 or just at aposition where the base member 104 and the locking device 108 are fullyengaged.

II. Method of Application to an End Portion of a Long Bone

FIGS. 8-16 illustrate various techniques for implanting the shoulderassembly 100 in a humerus H. The method illustrates placement in aproximal end of the humerus H, e.g., in the humeral head h.

FIG. 8 illustrates an early step of one embodiment of a method includingresecting the head h of the humerus H. Prior to resecting the head h ofthe humerus H a guide 600 is applied to the humerus H. The guide 600includes structure for mating with the humerus H and the head h, forexample, a plate 604 to mate with the humerus H and pins 608 to matewith the head h. The guide 600 also has a slot 612 to guide a saw to cutthe humerus H to expose cancellous bone of the head h. FIG. 9 shows thatafter resecting the head h of the humerus H the size of the head isevaluated with a template 620. To obtain a quick and accurate sizing, aguide pin 624 is first placed in the resected head h. The template 620is advanced over the guide pin 624 into contact with the resected head.The size of the resected head h is determined from the template 620. Theguide 600 can be a reusable guide that is not specific to any particularpatients. In other embodiments, the guide 600 is formed with referenceto a specific patient. That is, the guide 600 can be formed to mate withthe patient, such as by conforming in whole in part on a bone facingside to the shape of the bone as observed or measured using imaging orother devices prior to surgery.

FIG. 10 shows that the resected surface of the head h can be prepared,such as by using a planar or a reamer 632. The reamer 632 also can beguided by the guide pin 624. The reamer 632 can be used to form arecessed surface s to which the assembly 100 will be applied afterfurther preparation.

FIG. 11 shows a step of measuring depth of the recessed surface s. Thepurpose of this step is to provide a secondary confirmation that theassembly 100 will fit into the metaphysis without striking the lateralcortex. While the analysis of FIG. 9 indicates a diameter of base member104 that could be used, the depth gauge 637 of FIG. 11 provides a depthsizing that confirms a maximum length, e.g., depth, that would fit inthe recessed surface S surgeon is instructed to take the smaller of thetwo sizes determined.

FIG. 12 illustrates that following depth measurement, a bore b is formedin the surface s in initial preparation of the surface s to receive theshoulder assembly 100. The bore b is formed using a drill 640. The drill640 can be a convention cannulated design configured to be advanced overthe guide pin 624. The drill 640 can be configured as a universal drillwith a modular stop to obtain variable lengths. The drill 640 can be oneof a plurality of drills, each drill of the plurality having a differentsize as appropriate. In certain methods, the process of forming the boreb and reaming the surface s as discussed above in connection with FIG.10 can be combined. For example, a drill 640 can have a reaming featuredisposed proximally of the bore forming features such that a continuousmotion toward the surface formed using the guide 600 can initially formthe bore b and subsequently form the surface s. FIG. 13 shows that oncethe bore b has been formed, the bore b can optionally be tapped to beprepared to receive the base member 104 of the shoulder assembly 100.The tapping process can be achieved by using a helical tap component 648that is advanced over the guide pin 624. The helical tap 648 can followthe form of the helical structure 224 of the base member 104 such thatthe base member 104 can be easily advanced into the bore. The helicaltap 648 can be secured to a shaft 654 that can be mounted to a motordriven drill or to a hand tool.

FIG. 14 shows a step of inserting the base member 104. The base member104 is secured to a distal end of an inerter 662. The inserter 662 has astem 666 that is threaded at a distal end thereof. The threads of thestem 666 can be mated with the tool interface 272 (see FIG. 7 ), e.g.,with threads of the tool interface. Preferably the stem 666 is enlargedat a mid-section thereof providing at least a shoulder that can matewith the inner raised portion 148 of the base member 104. A separatemember 668 of the inserter 662 is advanced over the stem 666 to the toolinterface 158, and the force of advancing the base member 104 thus canbe applied through the tool interface 272, through the inner raisedportion 148, through the apertures 124 or through more than one of these(or other) features of the base member 104. Splines 672 provide for goodgrip by the surgeon so that the surgeon can easily engage the stem 666to the tool interface 272. In another variation, a driver with atorqueing device at a proximal end couples at its distal end directlywith the tool interface 272, through the inner raised portion 148,through the apertures 124 or through more than one of these (or other)features of the base member 104 to enable more direct transfer of torqueto the base member. Preferably inserting the base member 104 into thebone includes placing the outer periphery 154 in the recessed surface s,e.g., at least partially recessed into the resected bone of the humerusH.

FIG. 15 shows that after the base member 104 has been inserted, thelocking device 108 can be inserted. The base member 104 is inserted by arotation of the member by rotation of the inserter which is directlyconnected to the base member as discussed above in connection with FIG.14 . The locking device 108 is inserted along the pathway by lineartranslation, e.g., by a movement along a generally straight axis withoutrotation. An inserter 680 is provided that has an enlarged head 682 thatcan be secured to or can just rest upon the proximal face of the annularmember 366 of the proximal support 132. The head 682 is then advancedover the splines 672 of the stem 666, with the stem 666 acting as anaxial guide. In order to implant the locking device 108 the first end382 of the arm 110 or arms is aligned with the aperture 124 or aperturesif more than one. The arms 110 are radially and circumferentiallytapered and the apertures 124 are sized for the wider proximal end ofthe arms. This configuration helps guide the locking device 108 into thebase member 104. The proximal end 684 of the inserter 680 in configuredfor impacting the locking device 108 into the base member 104.

FIG. 16 shows later steps of a method of implanting an anatomic shoulderprosthesis. After the base member 104 and the locking device 108 areplaced, an anatomic articular component 84 can be coupled with therecess 102. The anatomic articular component 84 comprises a convexsurface 90, analogous to the natural anatomy. The anatomic articularcomponent 84 is placed with an impactor 684A. Although shown as aseparate, dedicated device the insertion and impaction functionsillustrated in FIGS. 15 and 16 could be carried out by the same device.For example a contoured face to contact the surface 84 could have aportion configured for inserting the locking device 108 and/or the tray94. FIG. 16 shows an alternative step of a method of implanting areverse shoulder prosthesis. After the base member 104 and the lockingdevice 108 are placed, a reverse articular component 88 can be coupledwith the recess 102. In one form, the reverse articular component 88includes a tray 94. The tray 94 can be coupled with an articularcomponent 96 comprising a concave surface for articulating with aglenoid sphere disposed on a glenoid of a scapula (discussed furtherbelow). The tray 94 is placed with an impactor 684A. The reverseshoulder prosthesis including the shoulder assembly 100, the tray 94 andthe articular component 96 is shown in FIGS. 18A and 18B. A glenoidsphere 99 mated with a glenoid is shown in FIG. 18B. The shoulder jointprovides movement of the patient's arm by articulating the component 96over the glenoid sphere 99.

In one variation of these methods, assemblies, and kits the lockingdevice 108 is inserted at the same time as some or all of the reversearticular component 88 or at the same time as the anatomic articularcomponent 84. The locking device 108 can be a separate component that isloaded onto an inserter or impacting tool that can be previously loadedwith the reverse articular component 88 or the anatomic articularcomponent 84. The locking device 108 can be a separate component that isloaded onto an inserter or impactor with, but relatively moveable to,the reverse articular component 88 or the anatomic articular component84. The locking device 108 and the reverse articular component 88 can beformed as a monolithic structure that can be loaded together onto aninerter. The locking device 108 and the anatomic articular component 84can be formed as a monolithic structure that can be loaded together ontoan inerter.

III. Additional Apparatuses and Methods

FIGS. 19-23 illustrate a shoulder assembly 800 that is adapted forsecurement to a glenoid. The shoulder assembly 800 is similar to theshoulder assembly 100 described above, except as described differentlybelow. Any feature discussed above can be substituted in and supplementthe features of the shoulder assembly 800. The features of the shoulderassembly 800 can be substituted in and supplement the features of theshoulder assembly 100.

FIG. 19 shows that the shoulder assembly 800 can be implanted into aglenoid region g of a scapula SC. The shoulder assembly 800 includes abase member 804 and a plate member 808. The base member 804 has a medialend 816 and a lateral end 820. FIGS. 21-23 show that the base member 804includes a body 812 that extends between the medial end 816 and thelateral end 820. A lumen 822 extends in the body 812 from the lateralend 820 toward and in some cases entirely to the medial end 816. Adistal portion of the lumen 822 includes a threaded zone 823, discussedbelow. The base member 804 includes a helical structure 824, which isdisposed along the body 812 between the medial and lateral ends 816,820, respectively. The helical structure 824 extends from the medial end816 to the lateral end 820 in some embodiments. In some embodiments atool interface 826 is disposed lateral of a lateral end of the helicalstructure 824.

The base member 804 includes a first pathway 830 accessible from thelateral end 820 of the base member 804. The first pathway 830 isdirected toward the medial end 816 through the helical structure 824.The first pathway 830 can be located adjacent to an inner periphery ofthe helical structure 824, as discussed above. The first pathway 830 canbe partly defined by an outer surface of the body 812. The first pathway830 can be disposed generally transverse to the helical structure 824.The first pathway 830 extends in a space 832 between successive portionsof the helical structure 824. In one embodiment, a first segment 830A ofthe first pathway 830 is disposed through a proximal portion of thehelical structure 824, a second segment 830B of the first path 830 islocated medial of the first segment 830A, and a third segment 830C ofthe first path 830 is disposed medial of the second segment 830B. FIG.23A shows the segments 830A, 830B, 830C of the path 830 in more detail.

FIG. 23A also shows that the base member 804 can include one or morebarbs 835. The barbs 835 are configured to facilitate softer materialattachment. In some embodiment the internal portion of the base member804 couples with a structure made of a soft material, such aspolyethylene. One example of such an assembly is an anatomicconfiguration where a convex articular surface may be coupled with thescapula using the base member 804. Another example is a reverseconfiguration with an inverse bearing surface (e.g. polyethylene glenoidsphere). The mode of connection between the base 804 and an articular orother component can include an interference fit between the barbs 835and a projection of such component received in a space around which thebarbs 835 are located, as described in connection with FIGS. 8A and 8Bof WO2016/094739. In other embodiments the barbs 835 can be replacedwith mating threads, mating threads and fins and/or mating fins, asdescribed in connection with FIG. 2 of US20120221111. In otherembodiments, the barbs 835 can be replaced by a groove and a C-ring orother deflectable member that spans between the base member 804 and anarticular or other component as described in connection with FIGS. 4 and5 of WO2014/067951. The entireties of each of WO2016/094739,US20120221111, and WO2014/067961, including the specific portions ofeach reference noted above are incorporated by reference herein.

The plate member 808 has a flange 842 and a first arm 846 that projectsdistally, medially away from or generally in a direction of implantationof the plate member 808 from the flange 842. The plate member 808 canhave a second arm 846 that projects away from the flange 842. The firstarm 846 is configured to be disposed in the first pathway 830 when theplate member 808 is disposed adjacent to the lateral end 820 of the basemember 804. The first arm 846 is disposed through bone in the space 832between successive portions of the helical structure 824 when theshoulder assembly 800 is implanted.

The plate member 808 also includes a boss 850 that extends laterally ofthe flange 842. The boss 850 comprises an arcuate outer periphery 854and an aperture 858 that provides access to a lumen 862 through theaperture 858. The lumen 862 is defined by a tapered surface 864 thatmates with a glenoid sphere 870, as discussed below. In anotherembodiment, the glenoid sphere 870 and the boss 850 are configured suchthat the glenoid sphere 870 coupled with the outer surface of the boss850.

The glenoid sphere 870 comprises a recess 874 disposed on a medial sideand a convex side 878 disposed opposite the recess 874. The glenoidsphere 870 has a tapered surface 882 disposed within the recess 874. Thetapered surface 882 is partly disposed in the recess 874 and partlyextends medially of the recess 874. The tapered surface 882 is disposedon a projection 890. The boss 850 receives the projection of the glenoidsphere 870 therein. The tapered surface 864 on the boss 850 mates withthe tapered surface 882 on the medial side of the glenoid sphere 870 toform a connection between the glenoid sphere 870 and the plate member808. The mating tapered surfaces 864, 882 can form a Morse taperconnection between the glenoid sphere 870 and the plate member 808.

FIG. 23 illustrates further features of the shoulder assembly 800 thatrelate to connecting the components thereof together. The glenoid sphere870 has a lateral opening 892 at the convex surface 878. The opening 892extends to a lumen 894 that extends from the opening 892 to a medialopening 898. The lumen 894 includes a threaded zone 902 adjacent to themedial opening 898. The threaded zone 902 can be used to couple theglenoid sphere 870 with an inserter. That is the threaded zone 902 canbe threaded onto a corresponding threaded tip of the inserter. Whilethreads are shown, other couplers can be used, such as a bayonetcoupling in place of or along with the threaded zone 902.

A fastener 910 is used to secure the glenoid sphere 870, the platemember 808, and the base member 804 together. The fastener 910 includesa medial end 914 with a threaded zone 918 and a lateral end 922. Thelateral end 922 includes a tool interface 926.

The connection between the components of the shoulder assembly 900 isshown in FIG. 20 . The base member 804 can be advanced into the glenoidg following preparations similar to that discussed in connection with ofFIGS. 8-13 . Once so placed, the plate member 808 can be advanced intothe base member 804. The plate member 808 is advanced in a mannersimilar to the locking device 108. The arms 846 are advanced into thehelical structure 824. Following placement of the plate member 808 intothe base member 804, the glenoid sphere 870 can be mated to the platemember. The projection 890 can be advanced into the lumen 862 (see FIG.23 ). Once the projection 890 is placed in the lumen 862 the fastener910 can be advanced relative to the projection 890 and mated with thethreaded zone 823. Further advancing of the fastener 910 into thethreaded zone 823 induces a friction fit, e.g., a Morse taper, at thetapered surfaces 864, 882. In one embodiment, the threaded zone 918 ofthe fastener 910 engages first the threaded zone 902 of the glenoidsphere 870 and then mates with the threaded zone 823. In thatembodiment, if the threaded zone 918 inadvertently disengage from thethreaded zone 823 the back-out of the fastener 910 is limited such thatthe lateral end 922 of the fastener 910 does not protrude outside of theconvex side 878 of the glenoid sphere 870. For example, even if thethreaded zone 918 is disengaged form the threaded zone 834, lateralmotion of the fastener 910 will be limited when a lateral end of thethreaded zone 918 is disposed against a medial end of the threaded zone902. When in this position, in one embodiment the distance between thelateral end of the threaded zone 918 and the lateral end 922 of thefastener 910 will be less than the distance within the lumen 894 fromthe lateral end of the threaded zone 902 to the convex side 878 of theglenoid sphere 870. Thus, the disengaged state of the fastener 910 willnot result in the lateral end 922 protruding from the convex side 878.

The plate member 808 includes additional features for enhancingsecurement to the bone. The plate member 808 can includes one or moreapertures 920. The apertures 920 can receive bone screws to enhancesecurement of the plate member 808 to the bone, e.g., to the scapula SC.Advantageously, the bone screw will lock into the apertures 920 by athread engagement. In some embodiments, the locking mechanism will bemulti-directional providing the possibility to lock the bone screws at avariable angle from the axis of the flange 842. Additionally, the medialside of the plate member 808 can includes a textured surface 924 e.g.,coated or layered with a porous material in order to accelerate tissueingrowth such as bony ingrowth. Advantageously, the plate member 808could be manufactured by additive manufacturing to incorporate theporous surface 924.

Though shown in use to secure a hard material (e.g. ceramic, pyrocarbon,or metal) glenoid sphere 99 to a glenoid, the assembly 800 could be usedto secure a soft-material (e.g. polyethylene, polyurethane, PEEK)glenoid sphere. Though shown in use to secure a glenoid sphere 99 to aglenoid, the assembly 800 could be used to secure an atomic glenoid.Though shown in use to secure a glenoid sphere 99 to a glenoid, theassembly 800 could be used in other anatomy to achieve very secureconnection to relatively shallow layers of bone, which can includecancellous bone that is exposed during a procedure.

IV. Additional Applications

FIGS. 24-26 show a number of other applications for the prosthesisassemblies described herein. In particular, the shoulder assemblies 100,800 can be applied to other bones and joints.

FIG. 24 shows that a proximal femur f can be fitted with a prosthesisassembly 100 f similar to the prosthesis assembly 100. The prosthesisassembly 100 f is different from the shoulder assembly 100 in that itwould be configured more particularly for the proximal femur.

FIG. 25 shows that a distal humerus h or to a distal radius r can befitted with a prosthesis assembly 100 h, r similar to the prosthesisassembly 100. The prosthesis assembly 100 h, r is different from theshoulder assembly 100 in that it would be configured more particularlyfor the distal humerus or radius.

FIG. 26 shows that a distal femur df and/or to a proximal tibia t can befitted with a prosthesis assembly 100 df, 100 t similar to theprosthesis assembly 100. The prosthesis assemblies 100 df, t, aredifferent from the shoulder assembly 100 in that they would beconfigured more particularly for the distal femur or proximal tibia.Also, on both side of the knee joint, implant sizing such as threadsexternal diameter, core diameter, overall length could be sizedaccording to patient anatomy per pre-operative planning based onCT-scan, MRI or any other medical images modality.

FIG. 27 shows that a distal tibia dt and/or to a proximal talus tal canbe fitted with a prosthesis assembly 100 dt, 100 tal similar to theprosthesis assembly 100. The prosthesis assemblies 100 dt, tal, aredifferent from the shoulder assembly 100 in that they would beconfigured more particularly for the distal tibia or proximal talus.Also, on both side of the ankle joint, implant sizing such as threadsexternal diameter, core diameter, overall length could be sizedaccording to patient anatomy per pre-operative planning based onCT-scan, MRI or any other medical images modality.

Each of the applications illustrated in FIGS. 24-26 can employ theprosthesis assembly 800 with modifications similar to those discussedabove in connection with the prosthesis assemblies 100 h, 100 r, 100 f,and 100 t.

V. Performance of Embodiments Disclosed Herein

FIG. 28 shows comparative performance of embodiments disclosed hereinwith respect to a stemless apparatus that does not have the helicalstructures disclosed herein nor the locking devices. The graph showsmaximum tip out force which is measured by applying an off axis load ata known or prescribed fixed distance from a surface at or to which ashoulder assembly similar to the assembly 100 was implanted. The tip outforce represents the resistance of the device to tipping out or becomingdislodge from the surface when subject to off axis loading. The forceswere observed using a load cell or force transducer. As can be seen, theforce of one embodiment is more than four times the force that woulddislodge the conventional stemless component. This represents asignificant improvement in the retention of the apparatuses disclosedherein compared to conventional stemless design which rely to a largeextent on ingrowth for securement which can be sufficient some timeafter implantation but which can be subject to dislodgement prior tofull integration by ingrowth.

As used herein, the relative terms “proximal” and “distal” shall bedefined from the perspective of the humeral shoulder assembly. Thus,distal refers the direction of the end of the humeral shoulder assemblyembedded in the humerus, while proximal refers to the direction of theend of the humeral shoulder assembly facing the glenoid cavity when theassembly is applied to the humerus. Distal refers the direction of theend of the humeral shoulder assembly embedded in the scapula, whileproximal refers to the direction of the end of the humeral shoulderassembly facing the humerus when the assembly is applied to the glenoid.In the context of a glenoid component, the distal end is also sometimesreferred to as a medial end and the proximal end is sometimes referredto as a lateral end.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements, and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements, and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements, and/or steps areincluded or are to be performed in any particular embodiment.

The terms “approximately,” “about,” and “substantially” as used hereinrepresent an amount close to the stated amount that still performs adesired function or achieves a desired result. For example, the terms“approximately”, “about”, and “substantially” may refer to an amountthat is within less than 10% of, within less than 5% of, within lessthan 1% of, within less than 0.1% of, and within less than 0.01% of thestated amount. As another example, in certain embodiments, the terms“generally parallel” and “substantially parallel” refer to a value,amount, or characteristic that departs from exactly parallel by lessthan or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree,0.1 degree, or otherwise.

Some embodiments have been described in connection with the accompanyingdrawings. However, it should be understood that the figures are notdrawn to scale. Distances, angles, etc. are merely illustrative and donot necessarily bear an exact relationship to actual dimensions andlayout of the devices illustrated. Components can be added, removed,and/or rearranged. Further, the disclosure herein of any particularfeature, aspect, method, property, characteristic, quality, attribute,element, or the like in connection with various embodiments can be usedin all other embodiments set forth herein. Additionally, it will berecognized that any methods described herein may be practiced using anydevice suitable for performing the recited steps.

For purposes of this disclosure, certain aspects, advantages, and novelfeatures are described herein. It is to be understood that notnecessarily all such advantages may be achieved in accordance with anyparticular embodiment. Thus, for example, those skilled in the art willrecognize that the disclosure may be embodied or carried out in a mannerthat achieves one advantage or a group of advantages as taught hereinwithout necessarily achieving other advantages as may be taught orsuggested herein.

Although these inventions have been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present inventions extend beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the inventions and obvious modifications and equivalentsthereof. In addition, while several variations of the inventions havebeen shown and described in detail, other modifications, which arewithin the scope of these inventions, will be readily apparent to thoseof skill in the art based upon this disclosure. It is also contemplatedthat various combination or sub-combinations of the specific featuresand aspects of the embodiments may be made and still fall within thescope of the inventions. It should be understood that various featuresand aspects of the disclosed embodiments can be combined with orsubstituted for one another in order to form varying modes of thedisclosed inventions. Further, the actions of the disclosed processesand methods may be modified in any manner, including by reorderingactions and/or inserting additional actions and/or deleting actions.Thus, it is intended that the scope of at least some of the presentinventions herein disclosed should not be limited by the particulardisclosed embodiments described above. The limitations in the claims areto be interpreted broadly based on the language employed in the claimsand not limited to the examples described in the present specificationor during the prosecution of the application, which examples are to beconstrued as non-exclusive.

What is claimed is:
 1. A shoulder assembly comprising: a base membercomprising: a collar; a helical structure extending from the collar in adistal direction; and a first pathway projecting distally of the collarand through the helical structure adjacent to an inner peripherythereof, the first pathway being generally transverse to the helicalstructure and extending in a space between successive portions of thehelical structure; and a locking device comprising a proximal supportand a first arm projecting distally of the proximal support, the firstarm configured to be disposed in the first pathway projecting distallyof the collar when the proximal support is disposed adjacent to thecollar; wherein the first arm is disposed through bone in the spacebetween successive portions of the helical structure when the shoulderassembly is implanted.
 2. The shoulder assembly of claim 1, wherein thebase member further comprises an inner core projecting distally from thecollar, an outer periphery of the helical structure surrounding theinner core, the first arm being located between the outer periphery ofthe helical structure and the inner core.
 3. The assembly of claim 1,wherein the first arm comprises an inner edge and an outer edgepositioned radially outward of the inner edge, at least the outer edgeof the first arm disposed in the helical structure along the firstpathway.
 4. The shoulder assembly of claim 1, wherein the proximalsupport comprises an annular member.
 5. The shoulder assembly of claim1, further comprising a second arm, the second arm beingcircumferentially spaced apart from the first arm.
 6. The shoulderassembly of claim 1, wherein the proximal support comprises anengagement feature to engage the collar.
 7. The shoulder assembly ofclaim 1, wherein at least one of the first arm and the first pathwaycomprise an engagement feature to the other of the first arm and thefirst pathway.
 8. The shoulder assembly of claim 1, wherein the firstarm is disposed through bone between the collar and the helicalstructure.
 9. The shoulder assembly of claim 1, wherein the base membercomprises a recess projecting distally from the collar to a locationwithin the helical structure, the recess configured to couple with anarticular component.